Hydraulic transmission



Dec 24, 19 40: E, 055 2,226,481

HYDRAULIC TRANSMISSION Filed June 29, 1938 4 Sheets-Sheet 1 Dec. 24,1946. E2.-L.. ROSE HYDRAULIC TE iANSMISSION 4 Sheets- Sheet 2 Filed June29, 1938 +mmm E. L. ROSE HYDRAULIC TRANSMISSION Dec. 24, 1940,

Filed June 29, 1938 4 Sheets-Sheet 3 E. L. ROSE HYDRAULIC TRANSMISSIONFiled June 29, 1958 4 Shaet8heet 4 95 3mm fuJf/lf A ffasz,

Patented Dec. 24, 1940 UNITED STATES PATENT OFFICE 2,226,481 masuucTRANSMISSION Eustace L. Rose, Charleston, W. Va.

Application June 29, 1938, Serial No. 216,562 4 Claims. (on. 60-53) Thisinvention relates to a hydraulic transmission or fluid gear designedprimarily for use in connection with automotive vehicleabut it is to beunderstood that the transmission or fluid gear, in accordance with thisinvention is for employment in any connection for which it may be foundapplicable.

The invention aims to provide, in a manner as hereinafter set forth, ahydraulic transmission or fluid gear which will operate at unusuallyhigh speeds, as would be required for automotive use.

The invention further aims to provide a hydraulic transmission or fluidgear constructed in amanner to greatly reduce the velocity of therubbing surfaces between component parts thereof and which will allowfor high speed operation without undue wear.

The invention further aims to provide a hy draulic transmission or fluidgear with means for automatically maintaining the proper ratio balance,when operating under heavy loads, to prevent overloading of the primemover.

The invention further aims to provide, in a manner as hereinafter setforth, a hydraulic transmission which is simple in its construction andarrangement, strong, durable, compact, readily assembled and installedrelative to a prime mover, thoroughly efficient in its use, andcomparatively inexpensive to set up. Embodying the foregoing aims, aswell as other aims which may directly or indirectly hereinafter appear,the invention consists of the novel construction, combination andarrangement of parts to be more specifically referred to and illustratedin the accompanying drawings, wherein is shown an embodiment of theinvention, but it is to be understood that changes, variations andmodifications may be resorted to which fall within the scope of theinvention as claimed.

In the drawings:

Figure 1 is a sectional view of the transmission or gear taken on theline I--I Figure 2,

Figures 2, 3 and 4 are sectional views of. the.

transmission or gear taken respectively on lines 4 2-4, 3-3 and 4-4Figure l, and

Figures 5, 6 and 7 are sectional views of the transmission or gear takenrespectively on lines 55, 66 and I--I, Figure 2.

The transmission or gear includes a housing 50 A made up in foursections I; 2, 3 and 4 suitably secured together by the holdfast means4a. The section I is adapted to be bolted to the rear end of the engineor prime mover crank case, not

shown, and displaces the flywheel housing. The 55 latter is also knownas the bell housing. The

section 2 carries a stationary fluid transfer means to be referred towhich is located between a pair of rotatable units which also will bereferred to. The section 2 merges into or joins the section I at thepoint 5, which is the center line of the 5 control cylinders to bereferred to. The sections I and 2 house one of the units of said pair.The

7 section 3 houses the other unit of said pair and carries a fixed crankmember 8 for association with one of the units of said pair. The section1 4 houses a thrust bearing 1 and carries a tail shaft 8-.

The units of said pair are indicated at 9, III. The general constructionof the units is substantially the same and each is capable of acting 15as a pump or a motor. In the embodiment of the invention as shown theunit 9 constitutes the pump and the unit III the motor. The units 9,

Ill will be hereinafter referred to as pump and I motor unitsrespectively. The unit 8 is rotated 20 by the engine or prime mover andwill produce rotation of the unit ID by forcing fluid through a fluidtransfer means II, when a hollow bodily shiftable crank memberI2,'forming a part of unit 9 is displaced from a common center. 7 25 Thepump unit 9, with reference to Figure 1, and also toFlgure 4 is formedof a series of parts which bodily rotate as a whole, but certain of suchparts may be shifted or adjusted to travel in a circular path eccentricto the common center 30 of the unit. The parts of unit 9 which may beshifted or adjusted as aforesaid may be termed crank elements. Theseelements consist of an outer ring I3 and an inner ring I. The latteralso serves the purpose of a bearing race. 35

The ,ring I3 encompasses in spaced relation and has its side faces flushwith the side faces of the ring I4.

Accurately fitted endwlse between the rings I3,

I4 is a plurality of radially disposed spaced sepa- 40 rators I5 havingtheir ends I5a of arcuate form, ,which is to be the equivalent of asegment of an arc of a disc having a diameter equal to the lengthof theseparators.

The arcuate ends of the separators are indicated at It and clearly shownin Figure 4. The ends of the separators fulcrum on the rings I3, I4.

The outer ends of the separators I5 are grooved, as at I! for thepurpose of straddling a rib Ila integral with the inner face of ring I3for maintaining the location of the latter with respect to the ring I4.The structure consisting of the rings I 3, I4 and separators I5 arecarried by a roller bearing means I8 which is journaled on the shiftablehollow crank member 12. The latter fits into an axially arranged taperedopening 19a formed in a bodily movable shifting beam Zil. The crankmember if is provided with a peripheral groove a between the taperedpart it and the part 201) of largest outer diameter of said member. Thepart 2% is the rear portion of member l2 and it is spaced from theportion l9 by the groove 2%. A stop nut 2|, for the beam 2i" engageswith the member 52. the unit 9 a shaft element 22, a main body elementand a cover plate element 2 5 are employed and such elements rotateabout a common or fixed center. The shaft element 22, will behereinafter termed a shaft and which is the input or drive shaft for thepump unit. The main body element 23, hereinafter termed inner bodysection is arranged against the inner side surfaces of the ring i l andprojects outwardly to a point in close proximity to ring iii. The coverplate element 2 3, hereinafter termed outer body section is arrangedagainst the outer side surface of the ring Hi and projects outwardly toa point in close proximity to the ring iii. The shaft 22 includes areduced inner portion 26a which extends through and is of less diameterthan the inner diameter of crank member E2. The shaft 22 also includesan outwardly opening cup-shaped outer portion 25 of materially greaterdiameter than the portion Ma. The inner face of the shaft portion 25 issplined, as at 25a for accurately fitting the splined outer end of theengine crank shaft 26 whereby shaft 22 will be driven from shaft 26. Theshaft 22 intermediate its ends is formed with a spline seat 2'? on whichis fixed the inner body section 2-3. The shaft 22 has a reduced portion26 which is of a length to extend from the splined portion 2'? to andthrough the thrust bearing F and which will be more fully referred to.The inner body section 23 has a hub 29 which is journaled in a rollerbearing 38. The other journal support being taken on the crank shaftbearing The inner body section 23 is formed with an annular rim 3'2extending between the rings ii,

i i and towards the outer body section 25. The rim 32 forms section 2233of cup-shaped contour and of a depth equal to thewidth of the separatorsl5. The inner diameter of the rim,32 is of sufficient size to allow ringit to be shifted eccentrically to the common shaftcenter, apredetermined amount. Between the inner surface of the rim 32 and theouter surface of the ring i l bolting the outer body section 24 to therim 32 of the inner body section, as at33b. The separators f5 and thering it are fitted between the faces 35, respectively, cf the inner andouter body sections with a siida'ole, but sealing engagement.

Each chamber 33 has a fluid channel 36 (Figares 1 and 4). The fluidchannels pass through inner'body section 23 and communicate with thefluid transfer means Has shown in Figure l.

Th motor unit it is of the same general contraction as the pump unit- 9,with the exception,

To complete roller bearing ii i.

-discharged on the other.

has a tapered part if] intermediate its ends which that it is oppositelydisposed and the crank memher 6 has a fixed throw. The member 6 includesa tapered part 5a intermediate its ends which fits into an axiallyarranged tapered opening 6'0 formed in the section 3. The member t isformed with an annular peripheral groove la. The member 5 includes aportion lb of largest outer diameter which is the front portion ofmember 8. The groove la is interposed between the portions 6a and lb ofmember 5. Tnreadedly engaging with the member 6 and bearing againstsection 3 is a stop nut lc. The motor unit includes a shaft 3'!revolubly mounted around the shaft part 25 and which has a splined seatupon which is fixed the inner body section 3? of unit it. The section 39has a hub it-i which is journaled in the A hearing race member 52 forthe bearing ll is fixed in a central bore (42a through the fluidtransfer means i l. The race 52 is common to both bearings 36) and 3E.The motor shaft 3'! is of tubular form and provided with a cup t3 at itsout-erend and in which is formed a seat 53a for the thrust bearing E.The reduced portion 28, of pump shaft 22, passes through both the hollowmotor shaft 3? and the thrust bearing l and has mounted thereon abearing seat M. The outer of this shaft portion 28 is threaded toreceive the bearing seat 6 which after being properly adjusted is lockedin position by the lock washer and nut The object of this construction,to furnish an adjustable free running retaining means to maintain asealing engagement between the inner body sections 23 and 39, and thefluid transfer means i I, as indicated at 5'7, 1%, did and 5b.

The tail or output shaft it is journaled in the housing section 4 by thebearings 5i and 52 which have a speedometer drive gear arrangedtherebetween. The gear 53 constitutes a spacer for bearings 5!, 52. Astandard universal power transmission element isenow spiined on the rearend of shaft 8 with a slinger cup 55 being disposed between its hub, andthe inner race of bearing 52. All of the mounted on shaft 8 are securedin place by the nut The inner end of the output shaft terminates in acup 57, which is splined around its outer periphery to accurately fitthe female splined portion 57a of cup d3. This furnishes an outboard support to the motor shaft 3?, and puts the two the crank member ifdisplaced in the direction of 7 a definite center line 58, the chambers33, will be caused to expand on the upper side of the center line, frompoint 59 to '53, and will contract on the lower side from point 6% to59. in this manner, fluid is drawn into chambers 33 through the fluidchannels 38 on one side of the center line 58 and The fie-w of fluidthrough this pump can be regulated to any desired quantity to zero bymoving the crank memher if toward the common shaft center or the howreversed by a continued movement beyond center without reversing therotation of the pump.

The fluid transfer means it as before stated is interposed between thepump unit and the motor unit, and with reference to Figure 3 it includesa pair of arcuate shaped transfer ports 62 and 58, which coincide withthe channels 525, and have partitions or separators 5d and between theirends which accurately equal the diameter accuser.

the pump discharge, or high pressure side.

Neither the transfer port 62 or 63, is specifically,

the high, or low pressure port, but one always acting opposite to theother as would be the case whenthe crankmember I2 is movedacross centerto reverse the pump flow. The motor unit It, is a duplicate of the pumpunit shown in Figure 4, but has its crank member 8 fixed in a permanentoffset position, as shown in Figure 1. When the pump unit 9 is beingdriven by a prime mover, it will discharge no fluid if the crank member12 is moved to coincide with the shaft center 6i, but if the crankmember is displaced in either direction there will be a discharge, inproportion to the displacement, into one of the arcuate transfer ports62 or 83, Figure 3, through the fluid channels 35 of the pump unit, thisbeing termed the high pressure port. The fluid being non-compressiblewill pass through the fluid channels of the motor unit into the chambersof such unit. The pressure of the fluid acting to ex, pand the chambersin the motor unit will produce rotation in the motor unit, with a speedthat will receive the discharge from the pump. After these chambers passover the center line of the partition or separator 65, Figure 3, theywill begin to contract, returning the fluid to the opposite or lowpressure transfer port; where it will again be taken into the pump. Thefarther the crank member I! is displaced from the shaft center 8|, thegreater will be the pump unit discharge. whichwill drive the motor unitfaster to receive it. If the crank member I2, is brought to center thendisplaced to the opposite side, this will reverse the flow of fluidthrough the pump unit. 'The high pressuretransfer port will become thelow, and the low the high, this will produce reverse rotation in themotor, thus an infinitely variable speed of rotation, within certainlimits, can be obtained in either direction by displacing the crankmember ii to one side or the other of the shaft center 6|. In operationit is necessary that all voids in the pump and motor units as well asthe transfer ports be filled with fluid at all times. Some fluid is lostthrough leakage and lubrication and must be made up from some outside InFigure 2 the housing is shown as provided with a sump 5', on whichiscarried a reserve supply of fluid for leakage makeup, and to operate thehydraulic speed control, which will be hereinafter described. Aservo-pump 01 is carried by the housing. driven by a spiral gear Imounted on the end of the prime mover cam shaft in and is continuouslydriven so long as the prime mover is operated. The pump l1, takes thefluid from the sump it through a strainer I and discharges it through anoutlet ll, into the conducting ine it e 3) through the T "and conductingpipe 13 to the point R. Here the fluid enters the channel I! forcing therelief valve "from its seat and returns to the sumpthrough the channelTil. This flow of fluid is continuous during the operation of the0n,.and hasa lowleakage makeup fluid to enter the low pressure transferport. In this manner leakage makeup fluid is fed into the hydrauliccircuit at all times during operation, regardless of which way the fluidis circulating through the transfer ports.

'The pump unit crank member If (Figure 1), as previously described isfixed in the shifting beam 20. At either end of this shifting beam is acurved offset portion terminating on an integral hollow piston 84 and85. The center line through these pistons coincide with the center ofthe crank bearing l8 for the purpose of load balance. The shifting beam20 is slidably mounted in the cylinders 86 and 81 as shown in Figure 1,bolted to two oppositely disposed points on the case sections I and 2.The disposition of the cylinder chambers 88 and 89, is, to shift thebeam 20 endwise if the fluid from the pumpi'l is allowed to enter onewhile the other is placed into communication with the casing interior.

The flow of fluid to' and from the cylinder chambers 88 and 89 iscontrolled by a rock shaft 90, Figure 2, which is carried by thebearings 9| and 92 fixed in the housing section I. This shaft isdisposed to be actuated by a foot pedal or lever, not shown flxed on theend indicated at I3.

The rock shaft 90 has an enlarged central portion 94, accurately butslidably fitted in the boss 95 which is an integral part of the shiftingbeam These ports in reality are spiral grooves as Due to these spiralports, if the rock shaft were rotated slightly back orforth it would beequivalent to moving the p0rts endwise. Between the ports 95, 91 and 98are two lands 99 and I.

These lands are of a width which accurately cover the fluid channels Iand I02 formed in the beam 20. Fluid from the pump 61 enters a fluidchannel Hi3, provided in the rock shaft 80, through the fluid conductingpipe I, of which the other end is shown connectedito channel I05, Figure3. The fluid after entering channel M3 is conducted to the ports 96 and98, through the fluidchannels I05 and I01. If the rock shaft ll wasrotated forward, as indicated by the arrow 108, part of a revolution,the ports 96, 81 and '8 would be displaced endwise in relation to thechannels IOI and id! in a direction indicated by the arrow I. This wouldplace the fluid channel ill in communication with the casing interiorthrough the spiral port l'l, allowing the fluid in the beam cylinderchamber .8 to be discharged through the conducting pipe 0. The fluidchannel III is placed in commlmication with the spiral port 86, allowingfluid from the pump I1 to enter the beam cylinder charnber 89, through Ithe fluid conductingpipe Hi. This will cause the shifting beam 20 toshove in a direction following the ports until the fluid channels IN andI02 are again closed by the lands II and I". If the rock shaft berotated in the opposite direction the fluid channel II! will communicatewith the pump 1 through the spiral part II, while fluid channel iii willcommunicate with the casing interlor through the spiral port "I. Thiswill reverse the disposition of the beam cylinderchamberslland8l,causingthebeam2ltoshiftin the opposite direction untilthe fluid channels Ill and ill are closed by the lands l9 and i". In

the pump unit crank member I2, is caused to fol low up any endwisedisplacement of the spiral ports produced by rocking the shaft 90 to orfro. If the pump unit crank member 82 Figure 1 was displaced from thecommon shaft centeran amount equal to the fixed throw of the motor unitcrank member the driving ratio would be one to one, this being thestandard practice in automotive transmissions.

Where the load becomes too great for the prime mover, as would be thecase when climbing a steep grade, it is necessary to reduce this ratio.In this fluid transmission the ratio is reduced by shortening the throwof the pump unit crank member i2, which is accomplished by rocking theshaft so, the necessary amount in the required direction. The rock shaft$53, in addition to being manually controlled, has an automatic controlto prevent overloading the prime mover independently of the operator.When the transmission is operating, the fluid in the high pressuretransfer port, between the pump and motor units, will assume a pressurewhich is in proportion to the load being transmitted. The heavier theload, the higher becomes the fluid pressure. The transfer ports or and33 (Figure 3) communicate with opposite ends of a cylindrical bore H2through fluid chantransfer port is the high'pressure port the piston H5will be forced to the stop on the low pressure side. This will allow thehigh pressure .port to communicate with the centrally located outlet H8,and at the same time leave a seal between the two ports. The position ofpiston I 55, Figure 3, indicates that transfer port 62 is the highpressure port. If the transmission was reversed, transfer port 53 wouldbecome the high pressure port, forcing the piston Hi to the stop H5 andthereby make communication with the outlet 6. Fluid from the highpressure transfer port, regardless of which one it may be, willautomatically make communication with the outlet H8.

The fluid is conducted from outlet M8 by the pipe i E9 to the bottom ofa. cylinder [20, Figure 2, where it enters the chamber IZI. If the loadbeing transmitted by the fluid gears becomes excessive, this will causea pressure rise in'the chambe: m, which will force the piston 22 upward,compressing the reactance spring I23 (Figure 5) an amount in proportionto'the load. Fixed on the piston :22 is abracket I24. Directly over thisbracket I24 are two lugs I25 and l26,'which'are made integral to therock shaft 98.

These lugs are shown in-the neutral position. If the shaft 9e isrcckedin either direction, for forward or reverse; one or the other of thelugs, 3'25 or 525 will be brought intocontact with the bracket I28. Thereactance spring I23 is adjusted to impose a predetermined load on theprime mover, and when this is.-exceeded. the excess pressure from thetransfer port will act to compress the spring :23, allowing the bracketI24 to rise and rock the shaft 90 toward-the neutral position. Thisaction progresses until the shifting beam I8 has shortened the throw ofthe pump crank member 82, to a point where the load and ratio will be inthe proper balance with the prime mover.

2,228, 28]. this manner the shifting beam 26 which carries The housingsection 2 is provided with a suspension means 82'5 for the fluidtransfer meam H. The cylinders 85, iii in proximity to their inner endsare formed with peripheral flanges 32.

which are secured to the housing sections i, 2 by the holdfast means525.

The housing section 5 has an axial opening 130 into which extends thecup-shape portion 25 of the shaft 22. The wall of opening E30 isprovided with inset packing rings [3| which bear on said portion 25.

The annular rim 32 and the ring it constitute respectively outer andinner wall forming elements common to the chambers 33. The outerbody'section of the-units 9, iii constitute outer end wall formingelements common to the chembers 33. The inner body section of the unitsQ, it! constitute inner end wall forming elements common to the chambers33. The separators it constitute the front and rear walls of chambers33. The fluid channels for the chambers s3 are formed in the inner sidewalls of the chambers. The rings and partitions of each unit areslidably adjustable relative to the body sections of the wt. I

The, crank member 5 intermediate its ends is formed with a beveledperipheral portion do; which bears against the wall of a tapered opening5b formed with the section 8 oi. the housing A, The member s carries astop nut on its outer end which abuts housing section 3.- The outer bodysections of. the unit extend into peripheral grooves in. formed in thecrank members *3 and I2. The inner body sections of the units oppose theinner end surfaces of the crank members t and I2. The latter issuspended irorn and bodily moves with the shifting beam re.

The initial priming of the transmission is obtained by placing therequired amount of fluid in the sump S8 and starting the prime mover.The servo pump 81 will very shortly exclude the air and fill thechambers and channels with fiuid.

As heretofore set forth the structure defined provides for two rotatablehydraulic units, with a transfer means interposed between them totransfer fluid from one to the other. One unit is equipped with a hollowshaft, having a thrust bearing seat at its outer end, and acting also asa detainer. The other unit has as an element thereof a shaft whichextends through a central opening in the transfer means and theaforementioned other shaft and has an adjustable thrust bearing mountedon its free end to act as a retainer to maintain a sealing engagement,between the rotating units and the stationary transfer means. The thrusthearing as aforesaid engages the seat aforesaid.

with respect tothe operation of the structure, the transmission consistsof two rotating units d and I8 with the transfer means interposed be=tween them and with the aforesaid elements bein; held in sealingengagement by the means as referred to. The rotating unit 9 is adaptedto be driven by a prime mover and such unit acts as a variable volumepump. The rotating unit it is adapted to act as a fluid motor to receivefluid from thepump-and produce rotation.

The transfer-means has two arcuate posts 82' and N, these ports areadapted to carry the fluid to and fro between the pump and motor units.The fluid discharged from the pump n w through one of these ports andafter producing the-requiredrotation in the motor, it is carriedaround-to the other port, and will be backtothepmip.

The direction of rotation of the motor unit, is controlled by which waythe crank member I2 in pump unit 9 is moved from the center. Also.

the farther the crank member is displaced from the center, the greaterwill be the discharge from the pump, which will increase the rotation ofthe motor unit in proportion. Moving the crank member I2 back to center,the pump discharge will become nil, producing no rotationfin the motorunit. By continuing the crank movement to the opposite side of center,the pump unit will discharge into the opposite transfer port reversingthe flow of fluid and drive the motor unit in the opposite direction.The crank member I2 is carried by the shifting beam 20, which issupported in the cylinders 86 and 81. The cross-wise movement isobtained by admitting fluid under pressure, to the cylinder chamber 88,at the same time allowing an equal amount to escape from chamber 89 orreversing this procedure to move in the opposite direction. The servopump 61, is adapted to be driven by the prime mover and furnish fluidunder low pressure for leakage makeup, and to operate the crank shiftingbeam.

.The fluid supply is carried in sump 66, where it enters the intake 69and is discharged from the outlet Ill, passing through the fluidconducting pipes, II, I3 and I04.

. The fluid necessary for leakage makeup, is conducted by the T 12, tothe channel I9, where it will pass through the valve 80 or 8! to the lowpressure side of the circuit. I

All surplus fluid in the servo line will pass through the relief valveI6 and return to the sump through channel 11. Fluid from conducting pipeI04, enters the channel I03 in rock shaft 90, which leads to the controlvalve that actuates the crank shifting beam 20. This valve is housed bya boss 95 which is integral with the shifting beam andis adapted toproduce endwise motion to the beam by rocking the shaft 80.

The valve ports are in the form of a spiral, so that, rotation gives theequivalent to endwise movement.

when the ports are shifted endwise, servo fluid is communicated to oneend of the shifting beam,

while the other is opened to allow the fluid to discharge. Discharginfluid enters the spiral port 91 which spirals to the open ends of thevalve housing.

Spiral ports 96 and 28, which carry the servo fluid, end blindly withinthe boss 95.

The fluid channels "II. and I02 are normally in the closed position butdue to the fact that they are in the shifting beam, any endwise movementof the spiral ports will set up a communication of fluid channels thatwill cause the shifting beam to follow the movement until the fluidchannels -Ifll and I02 areagain closed. In this manner any degree ofrocking'motion of shaft 90 will produce a proportionate amount ofcrosswise motion in the crank shifting beam.

It will be assumed that the transmission is installed in an automotivevehicle and there is a foot pedal mounted on the rock shaft 90 at theend 82.

when the operator starts the engine the servo pump 62 will also bedriven, furnishing fluid for the control valve on rock shaft 80. If theoperator desires to move forward, the foot pedal is rocked the desiredamount in the forward direction which will, through the control valvecausethe shifting beam to carry the crank member I2 oil center, settingup a discharge from the pump unit 9, which will act through the transfermeans to produce rotation in the motor unit I0. Rocking the foot pedalin the opposite direction from center position, will produce reverserotation for backing up. Also a variable speed ratio betweenv The fluiddischarge from the pump to themotor unit will create a pressure in thetransfer port in proportion to the load being transmitted. This pressurecommunicates through valve H8, fluid conducting pipe II9 to the lowerend of cylinder I20. As the pressure increases, it will act to forcepiston I22 upward against the reactance spring I23. The greater the loadbeing driven the higher will become the pressure, compressing thereactance spring in proportion. Piston I22 has a bracket I24, mountedthereon, which-is adapted to contact the lugs I25 and I26, which areintegral with the rock shaft 90. If the rock shaft is rocked off ofcenter position in either direction in case of overload, the bracket I24will contact one of the rock shaft lugs, forcing the shaft towards theneutral position. If the overload should become great'e'nough, the rockshaft will be moved to the neutral position, so that there will be nodischarge from the pump unit 9.

What I claim is:

1. In a hydraulic transmission, a driven, rotatable fluid pumping'unit,'a'fluid-driven, ro-

tatable motor unit, a stationary fluid transfer means interposed betweenand transferring fluid from one unit to the other, said means having acentral opening, one of said units including a pant abutting said means,a hollow shaft having a thrust bearing seat at its rear end acting as adetainer, the other of said units including a part abutting said means,a driving shaft extendin through said opening and through said hollowshaft and having an adjustable [thrust bearing on its rear end engagingsaid seat, said bearing when adjusted constituting a retainer forpressing said parts into engagement with said means to thereby maintainsealing engagement between said means and units.

2. In a hydraulic transmission, a driven, rotatable fluid pumping unit,a fluid-driven, rotatable motor unit, a stationary fluid transfer meansinterposed between and transferring fluid from one unit to the other,said means having a central opening, one ofsaid units including a pantabutting said means, a hollow shaft having a thrust bearing seat at itsrear end acting as "a detainer, the other of said units including a partabutting said means, a driving shaft extending through said opening andthrough said hollow shaft and having an adjustable thrust bearing on itsrear end engaging said seat, said bearing when adjusted constituting aretainer for pressing said parts into-engagement with said means tothereby maintain sealing engagement between .said means and units, eachof said units including a hub extending into said opening, and bearingmeans interposed between said hubs and said transfer means.

3. In a hydraulic transmission, a driven, rotatable fluid pumping unit,a fluid-driven, rotatable motor unit, a stationary fluid transfer meansinterposed between and transferring fluid from one unit to the other,said means having acentral opening, one-of said units including a partabutting said means, a hollow shaft having a thrust bearing seat at itsrear end acting as a detainenthe other of said units including a partabutting said means, a driving shaft extending through said opening andthrough said hollow shaft and having an adjustable thrust bearing on itsrear end engaging said seat, said bearing when adjusted constituting aretainer for pressing said parts into engagement with said means tothereby maintain sealing engagement between said means and units, eachof said units including an inner and outer ring disposed in spacedrelation and having interposed therebetween and fulcruming thereagainstradially disposed spaced separators and an annular rim interposedbetween said rings and through which said separators slidably pass, thesaid rim, separators and inner ring of each unit coacting to provideindependent extensible and contractable fluid receiving chambers forcommunication with said fluid transfer means, said pumping unitincluding an adjustable crank member for adjusting the rings of suchunit ofl center with respect to the'axis of the unit for varying thearea of one chamber with respect to an adjacent chamber of such unit,said motor unit including a fixed crank member normally disposedeccentrically with respect to the axis of such unit for varying the areaof one chamber with repect to an adjacent chamber of such unit.

4. In a hydraulic transmission, a driven, rotatable fluid pumping unit,a fluid-driven, rotatable motor unit, a stationary fluid transfer meansinterposed between and transferring fluid from one unit to the other,said means having a central opening, one of said units including a partabutting said means, a hollow shaft having aaaaesi a thrust bearing seatat its rear end acting as a detainer, the other of said units includinga part abutting said means a driving shaft extending through saidopening and through said hollow shaft and having an adjustable thrustbearing on its rear end engaging said seat, said hearing when adjustedconstituting a retainer for pressing said parts into engagement withsaid means to thereby maintain sealing engagement between said means andunits, each of said units including an inner and outer ring disposed inspaced relation and having interposed therebetween and iulcrumingthereagainst radially disposed spaced separators and an annular riminterposed between said rings and through which said separators slidablypass, the said rim, separators and inner ring of each unit coacting toprovide independent extensible and contractable fluid re ceivingchambers for communication with Sat fluid transfer means, said pumpingunit including an adjustable crank. member for adjusting the rings ofsuch unit ofl center with respect to the ems of the unit for varying thearea of one chamber with respect to an adjacent chamber of such unit,said motor unit including a fixed crank member normally disposedeccentrically with respect to the axis of such unit for varying the areaof one chamber with respect to an adjacent chamber of such unit andmeans for adjustably positioning said displaceable crank memher offcenter in opposite directions with respect to the axis of the pumpingunit.

EUSTACE L. ROSE.

